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-rw-r--r--pimd/pim_rpf.c395
1 files changed, 395 insertions, 0 deletions
diff --git a/pimd/pim_rpf.c b/pimd/pim_rpf.c
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+++ b/pimd/pim_rpf.c
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+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * PIM for Quagga
+ * Copyright (C) 2008 Everton da Silva Marques
+ */
+
+#include <zebra.h>
+
+#include "if.h"
+
+#include "log.h"
+#include "prefix.h"
+#include "memory.h"
+#include "jhash.h"
+
+#include "pimd.h"
+#include "pim_instance.h"
+#include "pim_rpf.h"
+#include "pim_pim.h"
+#include "pim_str.h"
+#include "pim_iface.h"
+#include "pim_neighbor.h"
+#include "pim_zlookup.h"
+#include "pim_ifchannel.h"
+#include "pim_time.h"
+#include "pim_nht.h"
+#include "pim_oil.h"
+#include "pim_mlag.h"
+
+static pim_addr pim_rpf_find_rpf_addr(struct pim_upstream *up);
+
+void pim_rpf_set_refresh_time(struct pim_instance *pim)
+{
+ pim->last_route_change_time = pim_time_monotonic_usec();
+ if (PIM_DEBUG_PIM_TRACE)
+ zlog_debug("%s: vrf(%s) New last route change time: %" PRId64,
+ __func__, pim->vrf->name,
+ pim->last_route_change_time);
+}
+
+bool pim_nexthop_lookup(struct pim_instance *pim, struct pim_nexthop *nexthop,
+ pim_addr addr, int neighbor_needed)
+{
+ struct pim_zlookup_nexthop nexthop_tab[router->multipath];
+ struct pim_neighbor *nbr = NULL;
+ int num_ifindex;
+ struct interface *ifp = NULL;
+ ifindex_t first_ifindex = 0;
+ int found = 0;
+ int i = 0;
+ struct pim_interface *pim_ifp;
+
+#if PIM_IPV == 4
+ /*
+ * We should not attempt to lookup a
+ * 255.255.255.255 address, since
+ * it will never work
+ */
+ if (pim_addr_is_any(addr))
+ return false;
+#endif
+
+ if ((!pim_addr_cmp(nexthop->last_lookup, addr)) &&
+ (nexthop->last_lookup_time > pim->last_route_change_time)) {
+ if (PIM_DEBUG_PIM_NHT)
+ zlog_debug(
+ "%s: Using last lookup for %pPAs at %lld, %" PRId64
+ " addr %pPAs",
+ __func__, &addr, nexthop->last_lookup_time,
+ pim->last_route_change_time,
+ &nexthop->mrib_nexthop_addr);
+ pim->nexthop_lookups_avoided++;
+ return true;
+ } else {
+ if (PIM_DEBUG_PIM_NHT)
+ zlog_debug(
+ "%s: Looking up: %pPAs, last lookup time: %lld, %" PRId64,
+ __func__, &addr, nexthop->last_lookup_time,
+ pim->last_route_change_time);
+ }
+
+ memset(nexthop_tab, 0,
+ sizeof(struct pim_zlookup_nexthop) * router->multipath);
+ num_ifindex =
+ zclient_lookup_nexthop(pim, nexthop_tab, router->multipath,
+ addr, PIM_NEXTHOP_LOOKUP_MAX);
+ if (num_ifindex < 1) {
+ if (PIM_DEBUG_PIM_NHT)
+ zlog_debug(
+ "%s %s: could not find nexthop ifindex for address %pPAs",
+ __FILE__, __func__, &addr);
+ return false;
+ }
+
+ while (!found && (i < num_ifindex)) {
+ first_ifindex = nexthop_tab[i].ifindex;
+
+ ifp = if_lookup_by_index(first_ifindex, pim->vrf->vrf_id);
+ if (!ifp) {
+ if (PIM_DEBUG_ZEBRA)
+ zlog_debug(
+ "%s %s: could not find interface for ifindex %d (address %pPAs)",
+ __FILE__, __func__, first_ifindex,
+ &addr);
+ i++;
+ continue;
+ }
+
+ pim_ifp = ifp->info;
+ if (!pim_ifp || !pim_ifp->pim_enable) {
+ if (PIM_DEBUG_ZEBRA)
+ zlog_debug(
+ "%s: pim not enabled on input interface %s (ifindex=%d, RPF for source %pPAs)",
+ __func__, ifp->name, first_ifindex,
+ &addr);
+ i++;
+ } else if (neighbor_needed &&
+ !pim_if_connected_to_source(ifp, addr)) {
+ nbr = pim_neighbor_find(
+ ifp, nexthop_tab[i].nexthop_addr, true);
+ if (PIM_DEBUG_PIM_TRACE_DETAIL)
+ zlog_debug("ifp name: %s, pim nbr: %p",
+ ifp->name, nbr);
+ if (!nbr && !if_is_loopback(ifp))
+ i++;
+ else
+ found = 1;
+ } else
+ found = 1;
+ }
+
+ if (found) {
+ if (PIM_DEBUG_ZEBRA)
+ zlog_debug(
+ "%s %s: found nexthop %pPAs for address %pPAs: interface %s ifindex=%d metric=%d pref=%d",
+ __FILE__, __func__,
+ &nexthop_tab[i].nexthop_addr, &addr, ifp->name,
+ first_ifindex, nexthop_tab[i].route_metric,
+ nexthop_tab[i].protocol_distance);
+
+ /* update nexthop data */
+ nexthop->interface = ifp;
+ nexthop->mrib_nexthop_addr = nexthop_tab[i].nexthop_addr;
+ nexthop->mrib_metric_preference =
+ nexthop_tab[i].protocol_distance;
+ nexthop->mrib_route_metric = nexthop_tab[i].route_metric;
+ nexthop->last_lookup = addr;
+ nexthop->last_lookup_time = pim_time_monotonic_usec();
+ nexthop->nbr = nbr;
+ return true;
+ } else
+ return false;
+}
+
+static int nexthop_mismatch(const struct pim_nexthop *nh1,
+ const struct pim_nexthop *nh2)
+{
+ return (nh1->interface != nh2->interface) ||
+ (pim_addr_cmp(nh1->mrib_nexthop_addr, nh2->mrib_nexthop_addr)) ||
+ (nh1->mrib_metric_preference != nh2->mrib_metric_preference) ||
+ (nh1->mrib_route_metric != nh2->mrib_route_metric);
+}
+
+static void pim_rpf_cost_change(struct pim_instance *pim,
+ struct pim_upstream *up, uint32_t old_cost)
+{
+ struct pim_rpf *rpf = &up->rpf;
+ uint32_t new_cost;
+
+ new_cost = pim_up_mlag_local_cost(up);
+ if (PIM_DEBUG_MLAG)
+ zlog_debug(
+ "%s: Cost_to_rp of upstream-%s changed to:%u, from:%u",
+ __func__, up->sg_str, new_cost, old_cost);
+
+ if (old_cost == new_cost)
+ return;
+
+ /* Cost changed, it might Impact MLAG DF election, update */
+ if (PIM_DEBUG_MLAG)
+ zlog_debug(
+ "%s: Cost_to_rp of upstream-%s changed to:%u",
+ __func__, up->sg_str,
+ rpf->source_nexthop.mrib_route_metric);
+
+ if (pim_up_mlag_is_local(up))
+ pim_mlag_up_local_add(pim, up);
+}
+
+enum pim_rpf_result pim_rpf_update(struct pim_instance *pim,
+ struct pim_upstream *up, struct pim_rpf *old,
+ const char *caller)
+{
+ struct pim_rpf *rpf = &up->rpf;
+ struct pim_rpf saved;
+ pim_addr src;
+ struct prefix grp;
+ bool neigh_needed = true;
+ uint32_t saved_mrib_route_metric;
+
+ if (PIM_UPSTREAM_FLAG_TEST_STATIC_IIF(up->flags))
+ return PIM_RPF_OK;
+
+ if (pim_addr_is_any(up->upstream_addr)) {
+ zlog_debug("%s(%s): RP is not configured yet for %s",
+ __func__, caller, up->sg_str);
+ return PIM_RPF_OK;
+ }
+
+ saved.source_nexthop = rpf->source_nexthop;
+ saved.rpf_addr = rpf->rpf_addr;
+ saved_mrib_route_metric = pim_up_mlag_local_cost(up);
+ if (old) {
+ old->source_nexthop = saved.source_nexthop;
+ old->rpf_addr = saved.rpf_addr;
+ }
+
+ src = up->upstream_addr; // RP or Src address
+ pim_addr_to_prefix(&grp, up->sg.grp);
+
+ if ((pim_addr_is_any(up->sg.src) && I_am_RP(pim, up->sg.grp)) ||
+ PIM_UPSTREAM_FLAG_TEST_FHR(up->flags))
+ neigh_needed = false;
+ pim_find_or_track_nexthop(pim, up->upstream_addr, up, NULL, NULL);
+ if (!pim_ecmp_nexthop_lookup(pim, &rpf->source_nexthop, src, &grp,
+ neigh_needed)) {
+ /* Route is Deleted in Zebra, reset the stored NH data */
+ pim_upstream_rpf_clear(pim, up);
+ pim_rpf_cost_change(pim, up, saved_mrib_route_metric);
+ return PIM_RPF_FAILURE;
+ }
+
+ rpf->rpf_addr = pim_rpf_find_rpf_addr(up);
+
+ if (pim_rpf_addr_is_inaddr_any(rpf) && PIM_DEBUG_ZEBRA) {
+ /* RPF'(S,G) not found */
+ zlog_debug("%s(%s): RPF'%s not found: won't send join upstream",
+ __func__, caller, up->sg_str);
+ /* warning only */
+ }
+
+ /* detect change in pim_nexthop */
+ if (nexthop_mismatch(&rpf->source_nexthop, &saved.source_nexthop)) {
+
+ if (PIM_DEBUG_ZEBRA)
+ zlog_debug("%s(%s): (S,G)=%s source nexthop now is: interface=%s address=%pPAs pref=%d metric=%d",
+ __func__, caller,
+ up->sg_str,
+ rpf->source_nexthop.interface ? rpf->source_nexthop.interface->name : "<ifname?>",
+ &rpf->source_nexthop.mrib_nexthop_addr,
+ rpf->source_nexthop.mrib_metric_preference,
+ rpf->source_nexthop.mrib_route_metric);
+
+ pim_upstream_update_join_desired(pim, up);
+ pim_upstream_update_could_assert(up);
+ pim_upstream_update_my_assert_metric(up);
+ }
+
+ /* detect change in RPF_interface(S) */
+ if (saved.source_nexthop.interface != rpf->source_nexthop.interface) {
+
+ if (PIM_DEBUG_ZEBRA) {
+ zlog_debug("%s(%s): (S,G)=%s RPF_interface(S) changed from %s to %s",
+ __func__, caller,
+ up->sg_str,
+ saved.source_nexthop.interface ? saved.source_nexthop.interface->name : "<oldif?>",
+ rpf->source_nexthop.interface ? rpf->source_nexthop.interface->name : "<newif?>");
+ /* warning only */
+ }
+
+ pim_upstream_rpf_interface_changed(
+ up, saved.source_nexthop.interface);
+ }
+
+ /* detect change in RPF'(S,G) */
+ if (pim_addr_cmp(saved.rpf_addr, rpf->rpf_addr) ||
+ saved.source_nexthop.interface != rpf->source_nexthop.interface) {
+ pim_rpf_cost_change(pim, up, saved_mrib_route_metric);
+ return PIM_RPF_CHANGED;
+ }
+
+ if (PIM_DEBUG_MLAG)
+ zlog_debug(
+ "%s(%s): Cost_to_rp of upstream-%s changed to:%u",
+ __func__, caller, up->sg_str,
+ rpf->source_nexthop.mrib_route_metric);
+
+ pim_rpf_cost_change(pim, up, saved_mrib_route_metric);
+
+ return PIM_RPF_OK;
+}
+
+/*
+ * In the case of RP deletion and RP unreachablity,
+ * uninstall the mroute in the kernel and clear the
+ * rpf information in the pim upstream and pim channel
+ * oil data structure.
+ */
+void pim_upstream_rpf_clear(struct pim_instance *pim,
+ struct pim_upstream *up)
+{
+ if (up->rpf.source_nexthop.interface) {
+ pim_upstream_switch(pim, up, PIM_UPSTREAM_NOTJOINED);
+ up->rpf.source_nexthop.interface = NULL;
+ up->rpf.source_nexthop.mrib_nexthop_addr = PIMADDR_ANY;
+ up->rpf.source_nexthop.mrib_metric_preference =
+ router->infinite_assert_metric.metric_preference;
+ up->rpf.source_nexthop.mrib_route_metric =
+ router->infinite_assert_metric.route_metric;
+ up->rpf.rpf_addr = PIMADDR_ANY;
+ pim_upstream_mroute_iif_update(up->channel_oil, __func__);
+ }
+}
+
+/*
+ RFC 4601: 4.1.6. State Summarization Macros
+
+ neighbor RPF'(S,G) {
+ if ( I_Am_Assert_Loser(S, G, RPF_interface(S) )) {
+ return AssertWinner(S, G, RPF_interface(S) )
+ } else {
+ return NBR( RPF_interface(S), MRIB.next_hop( S ) )
+ }
+ }
+
+ RPF'(*,G) and RPF'(S,G) indicate the neighbor from which data
+ packets should be coming and to which joins should be sent on the RP
+ tree and SPT, respectively.
+*/
+static pim_addr pim_rpf_find_rpf_addr(struct pim_upstream *up)
+{
+ struct pim_ifchannel *rpf_ch;
+ struct pim_neighbor *neigh;
+ pim_addr rpf_addr;
+
+ if (!up->rpf.source_nexthop.interface) {
+ zlog_warn("%s: missing RPF interface for upstream (S,G)=%s",
+ __func__, up->sg_str);
+
+ return PIMADDR_ANY;
+ }
+
+ rpf_ch = pim_ifchannel_find(up->rpf.source_nexthop.interface, &up->sg);
+ if (rpf_ch) {
+ if (rpf_ch->ifassert_state == PIM_IFASSERT_I_AM_LOSER) {
+ return rpf_ch->ifassert_winner;
+ }
+ }
+
+ /* return NBR( RPF_interface(S), MRIB.next_hop( S ) ) */
+
+ neigh = pim_if_find_neighbor(up->rpf.source_nexthop.interface,
+ up->rpf.source_nexthop.mrib_nexthop_addr);
+ if (neigh)
+ rpf_addr = neigh->source_addr;
+ else
+ rpf_addr = PIMADDR_ANY;
+
+ return rpf_addr;
+}
+
+int pim_rpf_addr_is_inaddr_any(struct pim_rpf *rpf)
+{
+ return pim_addr_is_any(rpf->rpf_addr);
+}
+
+int pim_rpf_is_same(struct pim_rpf *rpf1, struct pim_rpf *rpf2)
+{
+ if (rpf1->source_nexthop.interface == rpf2->source_nexthop.interface)
+ return 1;
+
+ return 0;
+}
+
+unsigned int pim_rpf_hash_key(const void *arg)
+{
+ const struct pim_nexthop_cache *r = arg;
+
+#if PIM_IPV == 4
+ return jhash_1word(r->rpf.rpf_addr.s_addr, 0);
+#else
+ return jhash2(r->rpf.rpf_addr.s6_addr32,
+ array_size(r->rpf.rpf_addr.s6_addr32), 0);
+#endif
+}
+
+bool pim_rpf_equal(const void *arg1, const void *arg2)
+{
+ const struct pim_nexthop_cache *r1 =
+ (const struct pim_nexthop_cache *)arg1;
+ const struct pim_nexthop_cache *r2 =
+ (const struct pim_nexthop_cache *)arg2;
+
+ return (!pim_addr_cmp(r1->rpf.rpf_addr, r2->rpf.rpf_addr));
+}